Beverage concentrates

ABSTRACT

A beverage concentrate comprises (a) about 45 to 80 weight percent fructose; (b) about 15 to 50 weight percent water; and (c) about 1 to 25 weight percent flavoring. The concentrate has a water activity of about 0.6 to 0.8 and is pourable at 5° F.

This application is a continuation of application Ser. No. 000,611,filed Dec. 31, 1986, now abandoned.

FIELD OF THE INVENTION

This invention relates to beverages. More particularly, this inventionrelates to sweetened, fruit-flavored beverage concentrates intended fordilution with water before consumption.

BACKGROUND OF THE INVENTION

Sweetened fruit-flavored beverages such as lemonade, limeade, grapeade,etc. are commonly sold to the consumer in the form of a frozenconcentrate. Furthermore, many sweetened fruit-flavored beverages soldas ready-to-drink liquids are reconstituted locally from frozenconcentrates. The frozen concentrate form is chosen so frequentlybecause: (1) its reduced weight and volume reduces the cost of shippingand storage; and (2) it extends the shelf life of the beverage byretarding or eliminating microbial spoilage.

The extension of shelf life by maintaining the concentrates at commonfreezer temperatures of -5° to 15° F. (-21° to -9° C.) is widely used,but not widely understood. Bacteria, yeasts, and molds thrive at roomtemperature in aqueous sugar solutions having a neutral pH. Unless oneor more precautions are taken, the growth of microbes can rapidlyincrease to the point where the sweetened fruit-flavored beverageconcentrate is unfit for human consumption.

One precaution for extending shelf life is to aseptically pack theconcentrate in a sealed container. Aseptic packing requires a prolongedtreatment at relatively high temperatures which frequently adverselyaffects the flavor and texture of the concentrates. Accordingly, thismethod is rarely used.

A second method of extending the shelf life of a concentrate is toformulate it so it exhibits a low water activity. Water activity is theratio of the vapor pressure of water in a material to the vapor pressureof pure water at the same temperature. It is known that microorganismshave limits on their ability to prevent the loss of water from theircells. If the water activity of their environment is too low, the cellscannot regulate the water loss and either become dormant or die. Forexample, few bacteria can survive at water activities less than about0.85, few yeasts can survive at activities less than about 0.80, and fewmolds can survive at activities less than about 0.75. This method ofextending shelf life has not generally been employed because excessivedrying and very low moisture levels have been required to reduce thewater activity of a concentrate to less than about 0.8.

A third method of retarding or eliminating microbial growth is to addone or more preservatives to the concentrate. The most commonpreservatives used in fruit juices are the potassium and sodium salts ofsorbic, benzoic, and sulfurous acids. However, these preservativesimpart objectionable flavor at higher concentrations, especially at anacidic pH. Therefore, the use of preservatives to extend shelf life isnot widely practiced.

Because of the disadvantages associated with the above methods ofpreserving concentrates, the most common method of preservation remainsto maintain the concentrates at about -5° to 15° F. (-21° to -9° C.).This, of course, greatly increases the cost and inconvenience ofshipping and storing the concentrates. Furthermore, at thesetemperatures, the concentrates are generally very hard. This hardnessis, in turn, an inconvenience when the concentrate is diluted to formthe drinkable beverage. It is usually necessary to thaw the concentrateat room temperature for 10 to 30 minutes to make it pourable andremovable from its container before it is diluted.

Accordingly, there is a demand for a sweetened fruit-flavored beverageconcentrate which does not require common freezer temperatures forpreservation. There is also a demand for such a concentrate whichremains pourable even at common freezer temperatures.

Kahn, U.S. Pat. No. 4,235,936, issued Nov. 25, 1980, discloses amicrobiologically-stable beverage concentrate which is "semi soft" atfreezer temperatures. The concentrate comprises about 15 to 55 percentwater, sugar in a ratio to water of about 0.8 to 2:1, and flavoring. Atleast 10 percent of the sugar is fructose and at least about 50 percentof the sugar is either fructose or dextrose. The concentrate's microbialstability is said to be a result of its relatively low water activity ofabout 0.75 to 0.90. Kahn states that, although microbial stability isinversely proportional to water activity, the mouth-feel and taste ofthe concentrate are adversely affected at very low water activities andthat water activities of about 0.90 to 0.93 are preferred. Example 1 ofKahn illustrates an orange juice concentrate. When a 600 ml. sample ofthe concentrate was frozen at 5° F. (-15° C.) in a graduated cylinder,then removed to room temperature and placed in a horizontal position,none of the concentrate flowed out of the cylinder after 1 minute and125 ml flowed out after 3 minutes.

SUMMARY OF THE INVENTION

The general object of this invention is to provide an improved sweetenedfruit-flavored beverage concentrate. A more particular object is toprovide such a concentrate which need not be maintained at commonfreezer temperatures for preservation, but which, if stored at suchtemperatures, remains pourable.

I have discovered a beverage concentrate which has a water activity ofabout 0.6 to 0.8 and is pourable at 5° F. The concentrate comprises: (a)about 45 to 80 weight percent fructose; (b) about 15 to 50 weightpercent water; and (c) about 1 to 20 weight percent flavoring.

This concentrate does not need to be stored at freezer temperatures tohave an acceptably long shelf life. However, even when stored at 5° F.,the concentrate remains pourable.

DETAILED DESCRIPTION OF THE INVENTION A. Fructose

The beverage concentrate of this invention comprises about 45 to 80, andpreferably about 50 to 65, weight percent fructose. Fructose is anaturally occurring sugar which is used in the concentrate primarily forits sweetness. It is well known that fructose is the sweetest of thecommon sugars. For example, if sucrose (table sugar) is assigned asweetness level of 100, fructose has sweetness level of about 117 andglucose (dextrose) has a sweetness level of about 65. Furthermore, it iswell known that fructose has desirable flavor-enhancing properties.

Fructose also imparts to the beverage concentrates several veryimportant physical properties which are not imparted to the same degreeby other sugars such as sucrose, glucose, invert sugar, and corn syrups.In particular, fructose is primarily responsible for the relatively lowwater activity (and extended shelf life) of the concentrate and for itspourability at 5° F. (-15° C.). The term "pourability" is used to meanthe ability of the concentrate to flow completely out of an invertedopen container at a given temperature, excepting the portion which mayadhere to the walls of the container. There are, in turn, three majorproperties of fructose which affect water activity and pourability.

First of all, fructose has approximately one-half the molecular weightof sucrose, the most common sugar. In other words, a given weight offructose contains twice the number of molecules as the same weight ofsucrose. It is well known that dissolving a solute in a liquid depressesthe freezing point of the solution. It is also well know that freezingpoint depression is a colligative property in that it is a function onlyof the number of dissolved molecules in the solution and is notdependent upon the identity of the dissolved molecules. Accordingly, theuse of fructose as opposed to sucrose in the beverage concentratedoubles the freezing point depression. This depression in freezing pointhelps prevent the concentrate from freezing (and the resultanthardening) at common freezer temperatures.

A second important property of fructose in its high water solubility.For example, at 25° C., fructose has a water solubility of about 4.0g/ml whereas sucrose has a water solubility of about 2.1 g/ml. This highwater solubility makes fructose relatively resistant to crystallizationin aqueous solutions. As a consequence, the beverage concentrate of thisinvention generally is not subject to hardening due to crystallizationeven at common freezer temperatures.

A third important property of fructose is its high humectancy, i.e., itsgreat ability to bind water molecules. This property is believed to beat least partially due to the fact that fructose has two adjacenthydroxyl groups which increase the strength of hydrogen bonding betweenit and water molecules. Fructose's humectancy is, in turn, believed tobe primarily responsible for the concentrates relatively low wateractivity of about 0.6 to 0.8.

The choice of the optimal fructose concentration depends on severalfactors. Freezing point depression and reduction in water activityincrease as fructose concentration increase. However, crystallizationand the resulting hardening also increase as fructose concentrationincrease. Therefore, it is preferred to formulate the concentrate at afructose concentration close to the saturation point of the solution atabout 5° F. (-15° C.). This concentration depends on the identity andquantity of the flavoring and any other ingredients, but is generallyabout 50 to 65 weight percent.

Fructose concentration affects the ratio at which the concentrate isdiluted to produce a beverage having a desired sweetness. Generally, theconcentrate is diluted with about 3 to 5 parts by volume water.

The fructose may be added as a solid or as an aqueous solution such as afructose-containing corn syrup. Suitable fructose-containing corn syrupsinclude IsoSweet® 100 corn syrup (whose solids content is 42 percentfructose) and IsoSweet® 5500 corn syrup (whose solids content is 55percent fructose), both of which are commercial products of the A. E.Staley Manufacturing Company. The preferred source of fructose iscrystalline fructose, a commercial product which is essentially purefructose, because it optimizes the physical properties of theconcentrate for a given level of sweetness.

B. Water

The concentrate comprises about 15 to 50, and preferably about 20 to 40,weight percent water. These figures represent water from all ingredientsin the concentrate. Water contents above about 50 weight percent areundesirable because they generally cause the concentrate's wateractivity to exceed about 0.8. (Other things being equal, water activityis a function of water content). Water activities above about 0.8 areundesirable in a beverage concentrate because its shelf life isunacceptably short unless the concentrate is kept at freezertemperatures, is aseptically packed, or is treated with preservatives.Water contents above about 50 weight percent are also undesirablebecause the extra water adds to the volume and weight of theconcentrate, thereby increasing the cost of shipping and storage.

Water contents below about 15 weight percent are undesirable becausethere is insufficient water to fully solubilize the fructose. As aconsequence, the fructose crystallizes and the concentrate becomesoverly hard and non-pourable at freezer temperatures.

C. Flavoring

The term "flavoring" is used to describe fruit-flavoring agents such asfruit juices, fruit derivatives, flavoring extracts and oils, and othernon-sugar materials which contribute to the flavor of the concentrate.The concentrate generally comprises about 1 to 25, and preferably about3 to 15, weight percent flavoring, where the flavoring is on a drysubstance basis. Preferred flavorings include natural strength orconcentrated fruit juices such as lemon juice, lime juice, grape juice,orange juice, pineapple juice, apple juice, strawberry juice, raspberryjuice, cherry juice, passion fruit juice, and combinations thereof.

D. Optional Ingredients

In addition to fructose, water, and flavoring, the concentrates of thisinvention can comprise a number of other ingredients. A first optionalingredient is a sugar other than fructose. For example, sucrose,glucose, and maltose are especially suited. However, sugars other thanfructose, when used in conjunction with the fructose already present inthe concentrate, may produce a concentrate which is overly sweet. It ispreferred that fructose comprise essentially all of the sugar in theconcentrate.

Other optional ingredients include antimycotic agents, vitamins,minerals, fats, emulsifiers, starches, protein concentrates andisolates, salts, and antioxidants. Such ingredients are described indetail in Kahn, U.S. Pat. No. 4,325,936, issued Nov. 25, 1980.

E. Examples

These examples are illustrative only.

EXAMPLE 1

This example illustrates the preparation of a lemonade concentrate.

The following ingredients were mixed in an open pot:

    ______________________________________                                        INGREDIENT    WEIGHT (G)  WT. PERCENT                                         ______________________________________                                        Lemon Juice   473.2       55.0                                                Crystalline Fructose                                                                        171.1       19.9                                                Water         215.5       25.1                                                              859.8       100.0                                               ______________________________________                                    

The lemon juice was a commercial product sold under the trademark RealLemon by Borden, Inc. It contained approximately 8 wt. percent solidsand 92 wt. percent water.

The mixture was then slowly heated in the open pot to evaporate waterand to concentrate the mixture to a solids level of 65 wt. percent. Theresulting concentrate had the following composition:

    ______________________________________                                        INGREDIENT    WEIGHT (G)  WT. PERCENT                                         ______________________________________                                        Lemon Juice Solids                                                                          37.9        11.8                                                Crystalline Fructose                                                                        171.1       53.2                                                Water         112.5       35.0                                                              321.5       100.0                                               ______________________________________                                    

A sample of this concentrate was tested for water activity and was foundto have an activity of 0.77. The concentrate made a pleasant-tastinglemonade when diluted with 4 parts by volume water.

The concentrate was then tested for pourability using the methoddescribed in Kahn, U.S. Pat. No. 4,235,936, issued Nov. 25, 1980, atCol. 8, lines 7 et seq. Namely, a graduated cylinder of 600 ml capacitywas filled with the concentrate and placed in a freezer at 5° F. (31 15°C.) for 24 hours. The cylinder was then removed from the freezer to roomtemperature, immediately placed on a platform in a horizontal (0°)position, and the effluent collected in another graduated cylinder withthe volume noted at timed intervals. The results were as follows: 150 mlafter 1 minute and 346 ml after 3 minutes.

I claim:
 1. A beverage concentrate comprising:(a) about 45 to 80 weightpercent fructose; (b) about 15 to 50 weight percent water, and (c) about1 to 25 weight percent flavoring,said concentrate having a wateractivity of about 0.6 to 0.8 and being pourable at 5° F.
 2. The beverageconcentrate of claim 1 wherein the flavoring is selected from the groupconsisting of lemon juice, lime juice, grape juice, orange juice,pineapple juice, apple juice, strawberry juice, raspberry juice, cherryjuice, passion fruit juice, and combinations thereof.
 3. The beverageconcentrate of claim 2 consisting essentially of:(a) about 50 to 65weight percent fructose; (b) about 20 to 40 weight percent water; and(c) about 3 to 15 weight percent flavoring.
 4. The beverage concentrateof claim 1 wherein the source of said fructose is crystalline fructose.5. The beverage concentrate of claim 1 wherein said concentratecomprises about 50 to 65 weight percent fructose.
 6. The beverageconcentrate of claim 1 wherein said concentrate is essentially free of asugar other than fructose.
 7. A beverage concentrate comprising:(a)about 50 to 65 weight percent fructose; (b) about 20 to about 40 weightpercent water; and (c) about 3 to 15 weight percent flavoring;saidconcentrate having a water activity of about 0.6 to 0.8 and beingpourable at 5° F.
 8. The beverage concentrate of claim 8 wherein saidconcentrate is essentially free of a sugar other than fructose and saidflavoring is selected from the group consisting of lemon juice, limejuice, grape juice, orange juice, pineapple juice, apple juice,strawberry juice, raspberry juice, cherry juice, passion fruit juice,and combinations thereof.